Angewandte Chemie International Edition
© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Cover Picture (Angew. Chem. Int. Ed. 19/1999)
The cover picture shows a part of the structure of -polyurethane, (C4H8NH-COO)n, (C: black, N: blue, O: red, H: white), with a paper in the background that was published more than 50 years ago by Otto Bayer, in which he describes the synthesis of [m,n]-polyurethanes and compares these polymers with the [m,n]-nylons and [n]-nylons prepared by Carothers. Despite the structural simplicity of [n]-polyurethanes, this class of polymers has not been described until now, due to the unavailability of the monomers. A novel method for the synthesis of isocyanates, using di-tert-butyltricarbonate, was used to prepare the isocyanato alcohol monomers, starting from linear aliphatic amino alcohols. In situ polymerization of these monomers yielded the [n]-polyurethanes. More details on the synthesis and characteristics of this general class of polymers are reported by E. W. Meijer et al. on pages 2917 ff.